LiDon Technologies proposes to incorporate a nanosecond phase-frequency modulation fluorescence lifetime measurement technique to a bi-directional water flux measurement system developed by the principals of LiDon; the Trans-membrane Water and Ion Measurement System (TWIMS) (Philis, Wong & Yeates, 1999). The system is based on the measurement of the modulation of the temporal changes in the fluorescence of 8-amino-1,3,6-naphthalene tri-sulfonate (ANTS) in D2O, compared to H2O due to bi-directional transport of D2O and H2O across a membrane partition. ANTS is excited with 397 nm light emitted from a sinusoidally-modulated blue LED at MHz frequencies. The phase as well as the modulation factor of the emitted fluorescence at 514 nm are determined using a dual photomultiplier tube in conjunction with a cross correlation technique. In this Phase I feasibility project, LiDon will incorporate these electro-optical technologies to improve the sensitivity and temporal resolution of the system. In Phase II, the system will be further optimized and automated to enhance the novelty of the TWIMS while reducing its costs of production so that profitable systems can be manufactured to attain market competitiveness. The maintenance of homeostatic water transport across biological membranes is fundamental to life and abnormalities in trans-membrane transport lead to diseases in organs and tissues, including the lungs, intestine, kidneys, eyes, and brain. This system is targeted to a yet untapped market. This market is forecast to undergo substantial growth PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE